Cooling Fan Inoperative

Cooling Fan Inoperative (LCS) (3.6L Hybrid)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.

Circuit/System Description

The engine control module (ECM) commands the cooling fans ON depending on the engine cooling requirements. The ECM controls the cooling fan speed by commanding the cooling fan control module. The cooling fan control module supplies the power and ground circuits for both cooling fans. The ECM sends a pulse width modulated (PWM) signal voltage to the cooling fan control module. The cooling fan control module interprets the signal and operates the cooling fans at the commanded speed.

Diagnostic Aids

* The ECM has the capability of providing command to the fan relays even when a scan tool output control is being used. Always refer to the fan control command parameters on the scan tool to know which fans are being commanded ON by the ECM.
* When disconnecting or removing fuses and relays from a fuse block, always inspect the component electrical terminals for corrosion and the correct orientation in the fuse block. Test the mating electrical terminals for tightness.

Reference Information
Schematic Reference

Engine Cooling Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Cooling System Description and Operation (With HP5) (Description and Operation)Cooling System Description and Operation (Without HP5) (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information

Circuit/System Verification

1. Verify that DTC P0480, P0691, or P0692, is not set.

• If a DTCs is set, refer to DTC P0480, P0481, P0691, P0692, P0693, or P0694 (LCS) (P0480).

Note: There is a slight delay before the cooling fans activate and reach full speed.

2. Ignition ON, command the cooling fans ON with a scan tool. Verify that both cooling fans turn ON and operate at a high speed.

Circuit/System Testing

1. Ignition OFF, disconnect the cooling fan motor harness connectors X2 and X3 from the cooling fan control module.

Note: The following test must be performed on both cooling fans.

2. Connect a 30 A fused jumper between B+ and the cooling fan motor control circuit terminal 1. Connect a jumper wire between the cooling fan motor ground circuit terminal 2 and ground. Verify the cooling fan is activated at a high speed.

• If either fan does not operate, replace the appropriate cooling fan motor.

3. If both of the cooling fans test normal, test or replace the cooling fan control module.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Fan Control Module Replacement (HP5) (Service and Repair)
* Engine Coolant Fan Motor Replacement (HP5) (Service and Repair)Engine Coolant Fan Motor Replacement (LAT) (Service and Repair)Engine Coolant Fan Motor Replacement (LE5, LZ4, LY7) (Service and Repair)
* Control Module References (Programming and Relearning)